[SPECT in the study of pathology of the temporomandibular joint. The authors' personal experience].

Symptomatic temporomandibular joint dysfunctions may affect about 25% of the adult population, with a smaller though significant percentage of patients experiencing severe impairment. From 1986 through 1991, 107 patients with severe temporomandibular joint symptoms and with various temporomandibular joint disorders were evaluated with conventional radiology and with closed/open-mouth temporomandibular joint tomograms. Single-photon emission-computed tomography (SPECT) and planar imaging were performed on 32 patients using a rotating gamma camera equipped with a general purpose collimator. Transaxial, coronal and sagittal tomoscintigrams were reconstructed. Increased radiotracer uptake in the temporomandibular joint was regarded as a positive finding, and the intensity of temporomandibular joint activity was compared with that of adjacent calvarium using regions of interest. In the 32 patients submitted to scintigraphy, conventional radiology showed no pathologic patterns, while SPECT showed pathologic findings in 31 patients (97% of cases). The patient with normal temporomandibular joint findings on SPECT exhibited abnormal maxillary isotope uptake, ipsilateral to the symptoms. Our results indicate that SPECT is a simple, noninvasive, inexpensive and very sensitive screening test relative to the internal derangement of the temporomandibular joint. Moreover, it provides information which is not available by means of routine bone scans or X-ray studies. Thus, SPECT appears to be the modality of choice for patients whose clinical findings are equivocal or whose symptoms are unclear, and it can guide treatment strategies and be useful in the follow-up.